surge_deriv = [0.007
-0.015
0.004
0.00075
-0.0076
-0.2
-0.003
0.02
0.025
-0.0013
-0.001
0.053
0.17
0.0017
0.046
0.005
-0.01
-0.004
-0.01
0.002
0.0035
-0.0016];